Page 31 - CEREC Q3|2013

quarter 3 | 2013 | cerecdoctors.com | 29
Fig. 6: The preparation was
scanned and digitally
rendered, as shown on the
CEREC Bluecam screen
Fig. 4: A highly translucent IPS e.max
CAD ingot was selected that would
closely match the adjacent teeth
Fig. 5: A crown was designed with a
transparent facial surface to allow the
underlying dentin shade to show through
and create the color of the tooth
appeared at least reasonable, as there
was adequate tooth structure remaining
above the gingival margin to allow for at
least 3 mm of ferrule circumferentially.
Treatment Plan
Due to the large amount of lost tooth
structure and the exposed and inflamed
nerve, a treatment plan was devised that
included root canal therapy on the frac-
tured incisor, restoring the tooth with
a fiber post and build-up, and crown.
Lithium disilicate (IPS e.max CAD) was
chosen for strength and its enamel-like
esthetics, and the CEREC Blucam was
used to aid in the design and immediate
chairside fabrication of the restoration.
Clinical Protocol
A shade was taken of the tooth before
treatment began in order to avoid the
altered perception of value due to dehy-
dration of the teeth during the proce-
dure (Fig. 4). The shade did not have
to be exact in this case, since the IPS
e.max CADmaterial requires glazing and
staining for replication of natural tooth
color and characterizations.
Local anesthetic was administered to
the patient, and after the anesthetic was
fully effective, root canal therapy was
performed on tooth #10. If left untreated,
periodontal problems would have likely
resulted. In addition, this procedure
would aid in the excavation of a healthy
site for insertion of the fiber post, while
greatly decreasing the patient’s post-
operative sensitivity.
A fiber post and build-up were placed
to increase the flexural strength and resis-
tance form of the preparation. The post-
and-core system also enhanced the frac-
ture resistance of the final restoration.
Tooth preparation was performed for
a full-coverage lithium disilicate crown.
A chamfer was carefully sculpted and
refined interproximally and lingually,
while a feather margin was created
across the facial surface at the gingival
margin. This preparation design allowed
for a thin and nearly transparent restor-
ative layer (about 0.3 mm) that would
permit the natural dentin shade to show
through (Fig. 5). When the dentin shade
is appropriate, this makes blending
the restoration with the adjacent teeth
much more predictable when using a
high translucency ingot. This prepara-
tion design would also help avoid a lower
color value in the gingival third, which is
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